external rotation
looked from back above
Fig 1. Experimental task for data collection
A: 20Abd B: 90Abd
external rotation
torque muscle B muscle A A B onset of torque
different of onset (DifOnset)
Fig 2. Graphical example of the measurement for EMG onset of each muscle and different of onset (DifOnset). “A” shows EMG onset of muscle A and “B” shows EMG onset of muscle B, and then between A and B shows the different of onset (DifOnset) in both muscles.
20msec 0.2mV 20msec 0.2mV 20msec 0.2mV 20msec 0.2mV 20msec 0.2mV supraspinatus teres minor posterior deltoid infraspinatus middle trapezius
Fig 3. Typical EMG data for muscle activity during shoulder external rotation in 90 degrees abduction position (90Abd) from single subject. The filled triangles in figure show EMG onset of each muscle.
Fig 4. Comparison of the different of onset (DifOnset) during the external rotators in both positions (20Abd and 90Abd).
-20 0 20 40 60 80 (msec) * -20 0 20 40 60 80 (msec) * A: 20Abd B: 90Abd supraspinatus teres minor posterior deltoid infraspinatus middle trapezius supraspinatus teres minor posterior deltoid infraspinatus middle trapezius
